2027 Corvette
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2027 Corvette
Looks like GM is taking a page out of the Toyota/Lexus play book and plans to make their 2027 LS6 6.7L Corvette engine both Port and Direct injected. No need for a Catch Can for this engine.
https://www.corvetteforum.com/articl...ect-injection/
https://www.corvetteforum.com/articl...ect-injection/
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Cool but catch cans are absolutely useless if the goal is to avoid DI deposit buildup in a car with a properly designed factory PCV system.
Almost all of the deposits come from intake charge reversion coating the valves during VVT EGR operation and normal I/E opening/closing overlap. I can't say nothing comes from the PCV but I have extremely good evidence it doesn't matter at all for any observable or practical context.
Almost all of the deposits come from intake charge reversion coating the valves during VVT EGR operation and normal I/E opening/closing overlap. I can't say nothing comes from the PCV but I have extremely good evidence it doesn't matter at all for any observable or practical context.
Last edited by Striker223; Jan 3, 2026 at 06:40 AM.
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I agree and "a properly designed factory PCV system" being the key point. Unfortunately it's not properly designed in some engines, hence the reason why some add a Catch Can to at least partially correct the situation.
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Please go ahead and be specific what cars you think have a measurable benefit from a catch can in direct relation to keeping buildup off the valves.
I have seen countless port injected cars with simple check valve setups that actively pool oil in the intake tubes to some degree or more and because they are port that is okay/doesn't cause real problems. I have not seen a single DI car lacking a separator system from factory nor a single one where the system was working with any oil pooling in the intake tract.
A catch can physically can't do a damn thing to stop intake charge revision coking of the valves. Disabling VVT EGR via a tune will reduce it though....
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Well, I guess my '15 Vette must be one of the exceptions you noted. I typically drain about half the volume of my 2015 Corvette's Catch Can every 1500 miles or so. While it's a safe bet a Catch Can is not 100% efficient, it does help reduce the amount of oily funk being drawn into the air intake and past the intake valves.
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It is really wild how this immediately turned into a debate about the efficacy of catch cans when the thread title is "2027 Corvette" lol. People run catch cans on the 2UR-GSE, and it's both port and direct injected... I think that the fuel delivery alone doesn't determine whether you'd use one. I could be wrong, but I digress.
Anyways, this is definitely good news, as carbon build-up is something that I do not look forward to dealing with on our BMW or our Vette. I guess what's more exciting is that we're getting a much higher-displacement and supposedly very new V-8 for the Corvette. The LT2 is great, but it's got its drawbacks, like being direct injection only and having AFM. A new engine without those concerns would be appreciated.
I wonder if the Stingray will also get the new engine.
Anyways, this is definitely good news, as carbon build-up is something that I do not look forward to dealing with on our BMW or our Vette. I guess what's more exciting is that we're getting a much higher-displacement and supposedly very new V-8 for the Corvette. The LT2 is great, but it's got its drawbacks, like being direct injection only and having AFM. A new engine without those concerns would be appreciated.
I wonder if the Stingray will also get the new engine.
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I've seen numerous videos of modern Corvette engines that gone without a Catch Can (CC) for 50,000 or more miles and camera views of the inside of their intake system show a pretty oily scene (like pooling oil), along with intake valve stem coking. Eventually idle gets rough and the MAS and other intake components need servicing. This, and the fact I tend to keep my vehicles a long time, are what prompted me to install a CC on my Vette early on. I can't remember ever hearing about these issues on modern Toyota and Lexus engines. In any case, I'm glad to see GM is changing their injection design on the '27 LS6 engine.
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Riddle me this.....how would you react to an engine that has the entire PCV system, EVAP, and vac lines all only connected to one half of the engine with totally separated intakes/TBs and complete isolation of the two sides and yet both sides have identical carbon buildup?
How would you react if the sample size is 4 separate engines of the same type and all deposits are exactly the same on both halves of the engine?
What would your explanation be for the PCV oils having anything to do with the buildup in that situation? Also please leave explanations on how these engines all ranged from 38k-167k miles with consistent buildup levels and no running issues.
Just because you have some liquid oil in the tract doesn't mean it's contributing to carbon buildup whatsoever, it's actually likely acting as a limited solvent and provided it doesn't contaminate the MAF it won't cause an issue or more importantly buildup. GM as usual as an underperforming separator setup but it's not the cause of intake valve deposit buildup.
How would you react if the sample size is 4 separate engines of the same type and all deposits are exactly the same on both halves of the engine?
What would your explanation be for the PCV oils having anything to do with the buildup in that situation? Also please leave explanations on how these engines all ranged from 38k-167k miles with consistent buildup levels and no running issues.
Just because you have some liquid oil in the tract doesn't mean it's contributing to carbon buildup whatsoever, it's actually likely acting as a limited solvent and provided it doesn't contaminate the MAF it won't cause an issue or more importantly buildup. GM as usual as an underperforming separator setup but it's not the cause of intake valve deposit buildup.
Last edited by Striker223; Jan 5, 2026 at 06:01 PM.
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to get (somewhat lol) back on track i'm excited that a big V8 will be with us for awhile! looking forward to the output figures
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sorry but gotta say it's nagnetiks fault for adding that last statement about a catch can no longer being necessary! it's one of the oldest rules of the internet, if you wanna get someone talking post something "wrong" and they'll be much more eager to "correct" it lol... i only vaguely know that a catch can has something to do with filtering the air from the PCV but i've seen enough over the years to know it's one of those never ending disputes
to get (somewhat lol) back on track i'm excited that a big V8 will be with us for awhile! looking forward to the output figures
to get (somewhat lol) back on track i'm excited that a big V8 will be with us for awhile! looking forward to the output figures
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